Rebuilding the ignition switch (grisly details)

[Adam Reed]

I've been reading a lot of posts all of a sudden from folks with older Porsches having problems with their ignition switches. Well, my '66 hotrod is in the same boat, having turned 40 this year, and for the last month I've been struggling with very stiff and unwilling movement when I put the key in to start 'er up. At times I've had to jiggle the key back and forth many times before I could get the key to turn in the switch.

So I decided last weekend to take bull by horns and find out what's up with this switch. It turns out to be like most other parts in this car: from the golden age of handmade, simple and very robust design. What holds the switch together is especially simple: a snap ring at the rear and a bit of crimping between the two halves of the switch. That's it.

FIRST: get a piece of paper and make a diagram of what color wire goes where. THEN disconnect them all and remove the switch to a well lit, clean work location.

If you don't have electrical problems, just stiff or cranky motion, AND you haven't been spraying silicone or WD-40 or whatever in the switch to keep it alive, you don't need to dismantle the switch halves. Get a couple of large sewing needles and use them to carefully pull off the little lock ring at the rear of the switch. It's tiny, and I needed an eye loupe to see what I was doing. It will try and jump off and hide in your pile carpet, so be careful! Then the lock cylinder just pops out from the front. This first photo shows the rear of the switch:



That coppery looking shaft in the center is the lock cylinder's brass shaft. That's where the snap ring goes. You can see the ring and the label in the background.

This second photo shows the lock tumbler itself. It's all brass, and over the years, two things appear to have happened: The original grease dries out, and little grooves get worn on the cylinder and the housing it rides in. Then the plungers get hung up and drag instead of slide.



Oh, and all that crap you've been spraying in there desperately to try and keep the switch operational? bad idea. It will be a mess inside! If, like me, you did this, then you really need to uncrimp the two switch halves and go in and clean the electrical portion. Believe me, all that gunk went in there to live. WORST OF ALL is graphite powder. It conducts electricity! DUH!

Clean off the outer surface of the key cylinder, and the inside of the housing. I used Q-tips and rubbing alcohol. Use a small file, once the cylinder is cleaned up, to smooth off any wear marks on the surface. I had some pretty good grooves going, after 450K miles of starts! Then simply lube the cylinder, the brass lock parts, and the housing inside (I used moly grease, same stuff I use on wheel bearings), and slip the lock cylinder back inside the housing. The photo shows what the cylinder will look like after re-lubing. DON'T use Vaseline, first warm day it melts and disappears. Ask me how I know...

Use a pair of needlenose pliers to gently bend the snap ring back into a circle (removing it will have distorted it out of shape), then get it over the rear of the lock cylinder shaft (you can see the groove in the second photo) and push it down until it seats in the groove.

Reinstall and reconnect. You will be amazed. It feels like a new switch!

have fun out there!

Adam 912.Out.
'66 912, 2.2L of lightweight T4 fun!

[Paulporsche]

It's amazing how these things were designed and built. Good work.

[wreckah]

great write up!

thanks alot!

[ianc]

Nice job! These are my favorite kinds of posts,

ianc